Acetaminophen hepatotoxicity and acute liver failure

Safety and efficacy of topical diclofenac sodium 1% gel in knee osteoarthritis: a randomized controlled trial

BACKGROUND

Topical nonsteroidal anti-inflammatory drugs (NSAIDs) may provide an alternative to oral NSAIDs to relieve pain from osteoarthritis (OA), reducing systemic exposure. This 12-week, randomized, double-blind, parallel-group, multicenter trial examined the efficacy and safety of topical diclofenac sodium 1% gel (DSG) for symptomatic knee OA.

METHODS

Eligible patients were aged >/= 35 years with symptomatic Kellgren-Lawrence grade (KLG) 1 to 3 OA in 1 or both knees for >/= 6 months. Patients meeting entry criteria applied DSG 4 g or vehicle 4 times daily to the symptomatic knee(s). Primary endpoints were Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and physical function subscales and global rating of benefit at week 12. Pain on movement at week 4 was an additional primary endpoint for European regulatory purposes. Secondary endpoints included primary outcomes at weeks 1, 4, and 8; WOMAC stiffness subscale; spontaneous pain; global rating of disease; and global evaluation of treatment. Subanalyses were performed according to KLG, the number of knees treated, and age.

RESULTS

Four hundred twenty patients were randomly assigned to DSG (n = 208) or vehicle (n = 212). At week 12, DSG provided significantly greater reductions in WOMAC pain (52.6% vs 43.1%; P = 0.008) and physical function (49.7% vs 39.4%; P = 0.004) versus vehicle and provided significant improvements in most secondary endpoints. Treatment-related adverse events (AEs) were infrequent (DSG, 7.7%; vehicle, 4.2%), with application site dermatitis being the most common AE (DSG, 4.8%; vehicle, 0%). No treatment-related gastrointestinal or serious AEs occurred with DSG.

CONCLUSION

Topical DSG treatment provided effective pain relief and functional improvement of OA in 1 or both knees and was well tolerated, irrespective of disease severity or patient age.

Similarities in features of autism and asthma and a possible link to acetaminophen use

Autism and autism spectrum disorders are enigmatic conditions that have their origins in the interaction of genes and environmental factors. In this hypothesis, genes statistically associated with autism are emphasized to be important in inflammation and in innate immune pathways, including pathways for susceptibility to asthma. The role of acetaminophen (paracetamol) in an increased risk for asthma is described and a possible similar link to an increased risk for autism is suggested.

Clinical cases in acute intoxication

Over 2.5 million accidental and intentional drug-related poisonings are reported annually in the United States. Early diagnosis and management of patients who present with acute intoxication can significantly reduce both morbidity and mortality. The initial evaluation of patients with suspected or proven intoxications should focus on hemodynamic stability, mental status, and respiratory function. However, early recognition of toxic ingestion is paramount to implementing life-saving treatments. Important historical clues are often found in a social history that considers intravenous drug use, alcohol use, and any access or exposure to illicit substances. A patient's medication list should also be scrutinized for psychoactive or sedative medications, such as tricyclic antidepressants or opioids. In this article we present case-based discussions of the specific diagnosis and management of 5 commonly occurring acute intoxication syndromes.

An integrative genomic analysis identifies Bhmt2 as a diet-dependent genetic factor protecting against acetaminophen-induced liver toxicity

Acetaminophen-induced liver toxicity is the most frequent precipitating cause of acute liver failure and liver transplant, but contemporary medical practice has mainly focused on patient management after a liver injury has been induced. An integrative genetic, transcriptional, and two-dimensional NMR-based metabolomic analysis performed using multiple inbred mouse strains, along with knowledge-based filtering of these data, identified betaine-homocysteine methyltransferase 2 (Bhmt2) as a diet-dependent genetic factor that affected susceptibility to acetaminophen-induced liver toxicity in mice. Through an effect on methionine and glutathione biosynthesis, Bhmt2 could utilize its substrate (S-methylmethionine [SMM]) to confer protection against acetaminophen-induced injury in vivo. Since SMM is only synthesized in plants, Bhmt2 exerts its beneficial effect in a diet-dependent manner. Identification of Bhmt2 and the affected biosynthetic pathway demonstrates how a novel method of integrative genomic analysis in mice can provide a unique and clinically applicable approach to a major public health problem.

Pig liver xenotransplantation as a bridge to allotransplantation: which patients might benefit?

Acute liver failure is a potentially devastating clinical syndrome that, without liver transplantation (Tx), is associated with high mortality. Rapid deterioration in clinical status and a shortage of deceased human organs prohibits liver Tx in many patients. Bridging to liver Tx has been attempted by various approaches, for example, bioartificial liver support, extracorporeal pig liver perfusion, and hepatocyte Tx, but none of these approaches has convincingly improved patient survival. The orthotopic Tx of a genetically engineered pig liver could theoretically provide successful bridging. Immediate availability, perfect metabolic condition, adequate size-match and hepatocyte mass, and freedom from potentially pathogenic microorganisms could be assured. The advantages and disadvantages of bridging by pig liver Tx compared with other approaches are discussed. The selection of patients for an initial clinical trial of pig liver Tx would be similar to that of various prior trials in patients experiencing rapid and severe deterioration in liver function. The ability to give truly informed consent for a pig bridging procedure at the time of listing for liver Tx renders the patient with acute-on-chronic liver failure or primary allograft failure is a preferable candidate for this procedure than a patient who is admitted urgently with acute (fulminant) liver failure in whom consent may not be possible. Although several barriers to successful pig organ xenoTx remain, for example, coagulation dysfunction between pig and primate, if these can be resolved by further genetic engineering of the organ-source pigs, a pig liver may prove life saving to patients dying rapidly of liver failure.